Exemplary embodiments relate to a method of programming a nonvolatile memory device.
A nonvolatile memory device has advantages of random access memory (RAM) (e.g., enabling the writing and erasure of data) and read only memory (ROM) (e.g., retaining data even without the supply of power) and is widely used in storage media for portable electronic devices, such as digital cameras, personal digital assistants (PDAs), and MP3 players.
One memory cell of the nonvolatile memory device, unlike a typical memory device, can store data of multiple states of 2 bits or more. That is, data of several states can be stored by controlling the charge in the floating gate of the memory cell so that the threshold voltage has a different amount. The multi-level cell (hereinafter referred to as an ‘MLC’) program method is widely used because it can significantly increase the capacity of a nonvolatile memory cell. In the MLC program method, data of two or more logical pages is programmed in one physical page. However, if data of several logical pages is programmed in one physical page, the time that it takes to perform the program operation is long and complicated, and the number of distributions of the threshold voltage is increased. Accordingly, the width of a distribution of the threshold voltage is narrowed and a read margin is reduced, leading to a difficulty in reading data.